The national trend toward infants being born at lower gestational ages may have significant, negative consequences for infants with congenital heart disease – even those considered full-term.
A full-term pregnancy is one that goes between 37 and 40 weeks, but a Cincinnati Children’s Hospital Medical Center study finds that the death rate more than doubles in infants with congenital heart diseases born at 37 weeks compared to those born at 40 weeks.
James Cnota, MD, a pediatric cardiologist at the Cincinnati Children’s Heart Institute, presented his findings on Monday, November 16, at the annual meeting of the American Heart Association in Orlando. Cnota is also Associate Professor at the University of Cincinnati College of Medicine.
"Pediatric cardiologists traditionally have considered any full-term birth acceptable, with the same level of risk. That thinking may be wrong,” says Cnota. "Our results say that babies with heart defects are more likely to survive if the pregnancy reaches a full 40 weeks.”
Cnota analyzed 14.9 million live births in the United States between 2000 and 2003. Of these, 4,736 with congenital heart disease died in the first year of life. Death rates decreased with each successive week of gestation: 58 of every 100,000 live births at 37 weeks died, while 24 of every 100,000 live births at 40 weeks died.
"When congenital heart disease is diagnosed prenatally, pediatric cardiologists need to work with their obstetrical colleagues to understand how the final weeks of pregnancy affect outcomes and to devise strategies to optimize the length of pregnancy,” says Cnota.
The nation’s preterm birth rate has increased by 36 percent since the 1980s, and despite a decline since 2007, the number of babies born too soon continues to top more than 540,000 each year, according to the March of Dimes.